Catheter adapted for use with guide wire for accessing vessels

ABSTRACT

An ablation catheter adapted for use with a guide wire has a 3-D shaped portion that carries ring electrodes for ablating a vessel or tubular region, including the renal artery. The 3-D shaped portion, for example, a helical portion, enables the ring electrodes to contact an inner surface of the vessel at a plurality of locations at different depths along the vessel to form a conduction block without forming a closed conduction loop which would otherwise increase the risk of stenosis of the vessel. In one embodiment, the catheter has a lumen with entry and exit ports to allow the guide wire to pass through the lumen but bypass the 3-D shaped portion. In another embodiment, the catheter has outer bands providing side tunnels through which the guide wire can pass through.

FIELD OF INVENTION

The present invention relates to a catheter adapted for use with a guidewire for accessing vessels or tubular regions in a patient's body. Inparticular, the catheter has a 3-D shape that can be straightened beforeentering a vessel or a tubular region.

BACKGROUND OF INVENTION

Catheterization is used in diagnostic and therapeutic procedures. Forexample, a cardiac catheter is used for mapping and ablation in theheart to treat a variety of cardiac ailments, including cardiacarrhythmias, such as atrial flutter and atrial fibrillation whichpersist as common and dangerous medical ailments, especially in theaging population. Diagnosis and treatment of cardiac arrhythmias includemapping the electrical properties of heart tissue, especially theendocardium and the heart volume, and selectively ablating cardiactissue by application of energy. Such ablation can cease or modify thepropagation of unwanted electrical signals from one portion of the heartto another. The ablation process destroys the unwanted electricalpathways by formation of non-conducting lesions. Various energy deliverymodalities have been disclosed for forming lesions, and include use ofmicrowave, laser and more commonly, radiofrequency energies to createconduction blocks along the cardiac tissue wall. In a two-stepprocedure—mapping followed by ablation—electrical activity at pointswithin the heart is typically sensed and measured by advancing acatheter containing one or more electrical sensors (or electrodes) intothe heart, and acquiring data at a multiplicity of points. These dataare then utilized to select the endocardial target areas at whichablation is to be performed.

Another catheterization procedure is renal denervation (RDN). It is aminimally invasive, endovascular catheter based procedure usingradiofrequency ablation aimed at treating hypertension. The sympatheticsystem fuels the release of certain hormones that affect and controlblood pressure. In hypertension, the continued release of low-doseamounts of these hormones can increase blood pressure. Hypertension canbe controlled by diet, exercise and drugs. However, resistanthypertension (commonly defined as blood pressure that remains above goalin spite of concurrent use of three antihypertensive agents of differentclasses) requires more aggressive treatments, including surgery.Resistant hypertension is a common clinical problem faced by bothprimary care clinicians and specialists. As older age and obesity aretwo of the strongest risk factors for uncontrolled hypertension, theincidence of resistant hypertension will likely increase as thepopulation becomes more elderly and heavier.

It has been established that severing the renal nerves improves bloodpressure. However, this procedure involves surgery and all its attendantrisks, and often resulted in global sympathetic denervation below thechest. Being able to de-nervate, or silence, only the renal nervesthrough a catheter-based system is a crucial development. A smallcatheter is placed in the femoral artery and access to the nerves isgained through the renal artery. The nerves are embedded in the casingsor layers around the renal arteries. By passing an energy source intothe renal artery and transmitting a low-dose energy, radiofrequencyablation, through the catheter, inbound and exiting renal sympatheticnerves are impaired or “denerved” at selected locations along theirlengths. This causes reduction of renal sympathetic afferent andefferent activity and blood pressure can be decreased.

In both cardiac ablation and renal ablation, ablation along a closedinner circumference or a narrow band in a vessel or tubular region canlead to stenosis, including narrowing, tightening or stiffening of thevessel or tubular region. Accordingly, catheters with different 3-Ddesigns have been employed to form conduction blocks that trace openpatterns, such as a helical pattern, that can block radial paths ofconduction without forming a closed ring within the vessel. However,such 3-D designs typically require a supporting wire to hold the 3-Dshape, and a contracting mechanism or a dedicated lumen for the guidewire for straightening the catheter entering and advancing in thepatient's body, all of which undesirably increases the outer diameter ofthe catheter. With an increased outer diameter, use of the catheter canbe significantly limited.

Accordingly, there is a desire for a catheter having a collapsible 3-Dshape that can be used with a guide wire without an increase in theouter diameter of the catheter, or at least in the portion of thecatheter having the 3-D shape.

SUMMARY OF THE INVENTION

The present invention is directed to an ablation catheter adapted foruse with a guide wire. The catheter has a 3-D shaped portion thatcarries ring electrodes for ablating a vessel or tubular region,including the renal artery. The 3-D shaped portion, for example, ahelical portion, enables the ring electrodes to contact an innercircumferential surface of the vessel at a plurality of radial locationsat different depths along the vessel to form a conduction block withoutforming a closed conduction loop which would otherwise increase the riskof stenosis of the vessel.

The catheter of the presenting invention adapted for use with a guidewire, includes an elongated tubular member having a proximal portion, adistal tip section, and a 3-D shaped portion carrying ring electrodesbetween the proximal portion and the distal tip section, wherein theproximal portion and the distal tip section are each in longitudinalalignment with the guide wire except for the 3-D shaped portion whichextends around the guide wire. The 3-D shaped portion has shape memorywhich allows it to collapse or deform when subjected to external forcesand to reassume its predetermined shape with removal of the externalforces. The shape memory allows the 3-D shaped portion to be advancedinto a patient's body and vasculature with relative ease and injury tosurrounding tissue. And, because the guide wire does not extend throughat least the 3-D shaped portion of the catheter, the size and outerdiameter of that portion of the catheter need not be increased toaccommodate the guide wire.

In a detailed embodiment, the 3-D shape is a helix wherein the helix isadapted to coil around the guide wire. In a neutral state, the helix hasan expanded radius and a contracted axial length. When subjected to anexternal force, for example, a tensile force which longitudinallystretches the helix, the helix transits to a deformed state with acontracted radius and an expanded axial length, which provides the 3-Dshaped portion of the catheter with a less traumatic profile foradvancement in the patient's body. The catheter of the present inventionadvantageously allows the 3-D shaped portion to transit between theneutral and deformed states without interference from or with the guidewire.

In a more detailed embodiment, the tubular member has at least one lumenadapted to receive the guide wire through the proximal portion and thedistal tip section. The at least one lumen has a first port in theproximal portion of the tubular member and a second port in the distaltip section, wherein one of the ports is adapted to allow the guide wireto exit the at least one lumen to outside the tubular member and theother of the ports is adapted to allow the guide wire to enter the atleast one lumen from outside the tubular member.

In another more detailed embodiment, the proximal portion of the tubularmember has at least a first band providing a first outer side tunnel andthe distal tip section has at least a second band providing a secondouter side tunnel, wherein each of the outer side tunnels is adapted toreceive the guide wire therethrough.

The catheter may have additional lumens, for example, one lumen for anelongated support member preformed with the 3-D shape to support the 3-Dshaped portion of the tubular member, and another lumen for electrodelead wires or any other components that extend through the tubularmember.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the present invention will bebetter understood by reference to the following detailed descriptionwhen considered in conjunction with the accompanying drawings wherein:

FIG. 1 is a top plan view of a catheter in accordance with an embodimentof the present invention.

FIG. 2 is a top plan view of a 3-D shaped portion of the tubular memberof the catheter of FIG. 1.

FIG. 2A is an end cross-sectional view of a tubular member of FIG. 2,taken along line A-A.

FIG. 3 is a side cross-sectional view of a distal section of thecatheter of FIG. 1.

FIG. 3A is an end cross-sectional view of the distal section of FIG. 3,taken along line A-A.

FIG. 4 is a schematic pictorial of a catheter of the present inventionpositioned in a renal artery.

FIG. 5A is a side cross-sectional view of a catheter of the presentinvention in a vessel or tubular region prior to deployment.

FIG. 5B is a side cross-sectional view of the catheter of FIG. 5A afterdeployment.

FIG. 5C is an end cross-sectional view of the catheter of FIG. 5B, takenalong line X-X.

FIG. 5D is an end cross-sectional view of the catheter of FIG. 5B, takenalong line X-X.

FIG. 5E is an end cross-sectional view of the catheter of FIG. 5B, takenalong line X-X.

FIG. 5F is an end cross-sectional view of the catheter of FIG. 5B, takenalong line X-X.

FIG. 5G is an end cross-sectional view of the catheter of FIG. 5B, takenalong line X-X.

FIG. 6 is a top plan view of a 3-D shaped portion of a tubular member ofa catheter in accordance with another embodiment of the presentinvention.

FIG. 6A is an end-cross-sectional view of the 3-D shaped portion of FIG.6, taken along line A-A.

FIG. 6B is a side view of a distal tip end of the catheter of FIG. 6.

FIG. 7 is a side cross-sectional view of a distal tip section withirrigated ring electrodes, in accordance with another embodiment of thepresent invention.

FIG. 7A is an end sectional view of the distal tip section of FIG. 7,taken alone line A-A.

DETAILED DESCRIPTION OF THE INVENTION

With reference to FIG. 1, this invention shown and described hereinrelates to a catheter 10 having an elongated catheter body 12, a distaltip section 15 with a 3-D configuration, e.g., a 3-D portion 17 (forexample, a helical configuration in the illustrated embodiment) withring electrodes 21, and a control handle 16. In accordance with afeature of the present invention, the 3-D portion 17 is adapted forablating an inner surface of a vessel or tubular region to block radialconduction lines without forming a closed loop line of block which mayotherwise cause stenosis of the vessel or tubular region.

With reference to FIGS. 2 and 2A, the catheter body 12 and the 3-Dportion 17 comprises an elongated tubular construction provided by amulti-lumened tubing 20 (preferably unbraided for at least the portion17) with at least two lumens, one of which is dedicated to a guide wire23. In the illustrated embodiment, there are three lumens 24, 25 and 26,where lumen 25 is dedicated to the guide wire 23. The catheter body 12is flexible, i.e., bendable, but substantially non-compressible alongits length. The catheter body can be of any suitable construction andmade of any suitable material. A presently preferred construction, thetubing 20 is made of polyurethane or PEBAX and may comprise an imbeddedbraided mesh of stainless steel or the like to increase torsionalstiffness of the catheter body so that, when the control handle 16 isrotated, the catheter body 12 will rotate in a corresponding manner.

The outer diameter of the catheter body is not critical, but ispreferably no more than about 8 french, more preferably 5 french. Thesize of each lumen is not critical, provided the lumens can accommodatethe respective components(s), including the guide wire 23, and forexample, lead wires 40 for the ring electrodes 21 and an elongatedsupport member 27 with shape memory to provide the 3-D configuration,such as the helical configuration of the portion 17 of the distalsection 15. A preferred shape memory material is nitinol, which hasexcellent ductility, strength, corrosion resistance, electricalresistivity and temperature stability. A nitinol wire for use as thesupport member 27 has preferably a square cross-section (e.g., about0.009 inch×0.009 inch) although the cross-section may also be circularor rectangular (e.g., with a width or diameter between about 0.006 inchand 0.012 inch). In one embodiment, the nitinol wire is preformed with ahelical shape having a diameter of about 10 mm.

The ring electrodes 21 are carried on an outer surface of the tubing 20on the 3-D portion 17 of the distal section 15. The lead wires 40 extendfrom the control handle 16, through the catheter body 12 and the helicalproximal portion via the lumen 26. One method for attaching a lead wire40 to a ring electrode 21 involves first making a small hole 30 (seeFIG. 2) in and through a side wall of the tubing 20. Such a hole can becreated, for example, by laser drilling or inserting a needle throughthe tubing 20 and heating the needle sufficiently to form a permanenthole. The lead wire 40 is then drawn through the hole by using amicrohook or the like. The end of the lead wire 40 is then stripped ofany coating and welded to the underside of the ring electrode 21, whichis then slid into position over the hole and fixed in place withpolyurethane glue or the like. Alternatively, each ring electrode 21 maybe formed by wrapping the lead wire 40 around the outer surface oftubing 20 a number of times and stripping the lead wire of its ownnon-conductive coating on its outwardly facing surfaces. In such aninstance, the lead wire 40 functions as a ring electrode. The pluralityof ring electrodes ranges between about 5 to 12, and more preferablyabout 8 to 10.

The support member 27 extends from the control handle 16 to the distalsection 15. However, it is understood that the support member 27 mayhave its proximal end at other locations throughout the catheter body12. In one embodiment, the proximal end is located in the catheter body12 about 25 mm proximal of the 3-D portion 17.

The support member 27 is preshaped with a 3-D configuration which isimparted to the tubing 20, including the portion spanning the 3-Dportion 17. The support member has shape memory so that such that itelastically holds the 3-D configuration (or any other preformed shape)when no external forces are applied, assumes another or deformed shapewhen an external force is applied, and returns to the preformed shapewhen the external force is removed. In the illustrated embodiment, thesupport member 27 has a helical distal portion which 3-D configurationis imparted to the portion 17. Because of the shape memory of thesupport member 27, the helical portion 17 is elongated and straightenedupon application of an external force (e.g., a tensile force and/or acompression force), and rebounds to its initial shape when the externalforce is removed. A distal end of the support member 27 is potted andanchored at the distal end of the tubing 20 in the lumen 24 by a plug 36of adhesive, sealant or glue, such as epoxy, as shown in FIGS. 3 and 3A.

The dedicated lumen 23 for the guide wire 23 extends the entire lengthof the tubing 20. However, when the catheter is used with the guide wire23, the lumen 23 is occupied by the guide wire 23 only in the catheterbody 12 and at or near the distal end of the tubing 20. As shown inFIGS. 2 and 3, proximal exit port 38 and distal entry port 39 are formedin and through the side wall of the lumen 23 in the tubing 20immediately proximal and immediately distal of the helical portion 17.As such, the guide wire 23 can be received in the lumen 23 throughoutthe catheter body 12, exit the lumen 23 and the catheter at exit port 38to bypass the helical portion 17 and re-enter the lumen 23 at entry port39.

As also shown in FIGS. 3 and 3A, the generally straight distal portion19 of the distal section 15 includes a short section of a single lumenedtubing 32 whose proximal end is attached to a distal end of themulti-lumened tubing 20 of the helical portion 17. A central lumen 34 ofthe tubing 32 is generally sealed at its distal end by a dome plug 50 ofsealant or glue, such as epoxy, except for an axial distal tip exit port52 for the guide wire 23 to exit the catheter at the distal tip end. Itis understood that the distal end of the support member 27 may extendinto the dome plug 50 and anchored therein. It is also understood thatthe distal tip section need not have the generally straight distalportion 19 and that the dome plug 50 may be positioned at the distal endof the helical portion 17.

FIG. 4 illustrates vessels or tubular regions in a patient's body,namely, aorta 58, and renal artery 54 extending into kidney 60. Accessedvia the aorta 58, the renal artery 54 is a target site for renaldenervation by means of catheter ablation. Prior to the catheterentering the patient's body and vasculature, the guide wire 23 isinserted into the catheter 10 distally from the control handle 16 andinto the catheter body 12, as shown in FIG. 1, so that the catheter canmove on and over the guide wire and be guided by the guide wire whichprecedes the catheter through the patient's vasculature. As shown inFIG. 2A, the guide wire travels through the lumen 23 through theentirety of the catheter body 12. The guide wire bypasses the helicalportion 17 by exiting via the proximal port 38 proximal of the 3-Dportion 17 and reentering the catheter via the distal port 39 distal ofthe helical portion. Because the guide wire is outside the helicalportion 17, the helical portion 17 is unconstrained and free of externalforces that would prevent it from assuming the 3-D configurationimparted by the support member 27.

Using standard guide wire procedures, or as the catheter enters thepatient's body and vascular, preceded by the guide wire 23 which may beused with a guiding sheath 57, as shown in FIG. 5A, a distal tip end ofthe catheter (as formed by the dome plug 50) is advanced into thevascular, followed by the generally straight distal section 19. Thegenerally straight distal portion 17 facilitates entry of the catheterinto the patient's body and vascular. Before the 3-D portion 17 entersthe patient's body, it is elongated in the axial direction andcontracted in the radial direction by the application of an externaltensile force in the proximal direction relative to the guide wire sothat the 3-D portion 17 presents a less traumatic/more atraumaticprofile as shown in FIG. 5A. As such, the 3-D portion 17 is moremaneuverable for advancement in the vascular and the catheter isadvantageously usable with a guide wire without requiring a larger outerdiameter in the 3-D portion to accommodate the guide wire.

At the treatment site with in lumen 53 of the vessel 54, the distalsection 15 is deployed by being moved distally past the distal end ofthe guiding sheath 57. The guide wire 23 is then drawn proximally sothat its distal end 22 slides back into the distal tip end port 52 andthrough the central lumen 34 of the generally straight portion 19. Thedistal end then exits the distal port 39 and back into the proximal port38 and the lumen 25. Without being guided and constrained by the guidewire 23, the 3-D portion 17 reassumes its 3-D shape when deployed, forexample, expanding in the radial direction and contracting in the axialdirection to return to the helical configuration as shown in FIG. 5B,where the ring electrodes 21 come into contact with an innercircumferential surface of the vessel 54. As shown in FIGS. 5C-5G, thehelical configuration enables each ring electrode 21 to contact adifferent radial location (for example, 360 degrees in FIG. 5C, 270degrees in FIG. 5D, 135 degrees in FIG. E, 90 degrees in FIG. 5F, and 15degrees in FIG. 5G) at a different depth along the vessel so thatresulting lesions 63 terminate nerves and/or form a block around thevessel without creating a closed circumferential loop that couldotherwise cause stenosis of the vessel. The shape memory support 27advantageously allows the 3-D portion 17 to have a preformed shape, bedeformed when subjected to an external force, and to reassume thepreformed shape when the external force is removed. It is understoodthat where the 3-D configuration is a helical configuration as shown inthe illustrated embodiment, the helical configuration can be coiledaround the guide wire 23 such that the guide wire extends through a loop(or loops) 56 of the helical configuration (as shown in FIGS. 2A and4A).

FIGS. 7 and 7A illustrated a distal tip section 15 with at least oneirrigated ring electrode 21′ having a plurality of fluid ports 70. Theirrigated ring electrode 21′ has a raised profile such that an annulargap 72 is formed between the ring electrode 21′ and an outer surface oftubing 20. Irrigation fluid is delivered to the ring electrode 21′ vialumen 28 which may be fed at its proximal end by irrigation tubing (notshown) from the control handle 16. The fluid is passed from the lumen 28to the annular gap via a passage 74 formed between the lumen and theirrigated ring electrode 21′. Fluid then passes to outside the ringelectrode 21 via fluid ports 70 formed in the ring electrode.

In an alternate embodiment of the present invention, as shown in FIGS. 6and 6A, a catheter 10′ includes a plurality of band or rings 61 mountedon an outer surface of the tubing 20, each of which provides an outerside tunnel 62 to couple the catheter and the guide wire 23. Thecatheter 10′ includes at least a proximal band or band 61P proximal ofthe 3-D portion 17 and at least a distal band 61D distal of the 3-Dportion 17 to provide outer side tunnels 62P and 62D. The catheter 10′may also include a distal end band 61T (FIG. 6B) at or near the domeplug 50 at the distal tip end of the catheter to provide outer sidetunnel 62T. In the illustrated embodiment, each band 61 has acircumference larger than the outer circumference of the tubings 20 and32, wherein the excess circumference is pinched (and glued) to securethe ring onto the tubings 20 and 32 and form the side loop or tunnelthrough which the guide wire 23 is inserted. Extending from the catheterbody 12 to the 3-D portion 17, the tubing 20 includes the lumen 24 forthe support member 27 and the lumen 26 for the lead wires 40. However,there is no lumen for the guide wire 23 because the guide wire 23extends outside of the catheter 20.

As the catheter 10′ enters the patient's body and vascular, preceded bythe guide wire which may be used with a guiding sheath 57, the 3-Dportion 17 is similarly elongated in the axial direction and contractedin the radial direction by the application of an external tensile forcein the proximal direction relative to the guide wire so that the 3-Dportion 17 presents a less traumatic/more atraumatic profile. When the3-D portion 17 reaches the treatment site, the portion 17 is movedbeyond the distal end of the sheath 57 and the guide wire is drawnproximally relative to the catheter 10 until the distal tip end slidesout of the distal end tunnel, the distal tunnel and then out of theproximal tunnel, whereupon the 3-D portion 17 shortens in the axialdirection and expands in the radial direction to return to its original3-D configuration. As with the catheter 10, the ring electrodes 21 ofthe catheter 10′ come into contact with an inner surface 55 of thevessel 54. The helical configuration enables the ring electrodes 21 tocontact a plurality of radial locations at different depths along thevessel so that resulting lesions form a block around the vessel withoutcreating a closed loop that could otherwise cause stenosis of thevessel.

The ring electrodes 21 are constructed of a biocompatible metal,including a biocompatible metal alloy. A suitable biocompatible metalalloy includes an alloy selected from stainless steel alloys, noblemetal alloys and/or combinations thereof. In another embodiment, the tipelectrode is a shell is constructed of an alloy comprising about 80%palladium and about 20% platinum by weight. In an alternate embodiment,the shell is constructed of an alloy comprising about 90% platinum andabout 10% iridium by weight. The rings may be uni-polar or bi-polar. Inthe illustrated embodiment, there are 10 ring electrodes forming fivepairs of bi-polar ring electrodes. Each ring electrode is connected to arespective lead wire. The tip electrode is electrically connected to asource of ablation energy and/or an appropriate mapping or monitoringsystem by respective lead wires.

The preceding description has been presented with reference to presentlypreferred embodiments of the invention. Workers skilled in the art andtechnology to which this invention pertains will appreciate thatalterations and changes in the described structure may be practicedwithout meaningfully departing from the principal, spirit and scope ofthis invention. In that regard, the drawings are not necessarily toscale. Accordingly, the foregoing description should not be read aspertaining only to the precise structures described and illustrated inthe accompanying drawings, but rather should be read consistent with andas support to the following claims which are to have their fullest andfair scope.

What is claimed is:
 1. An ablation catheter adapted for use with a guidewire, the catheter comprising: an elongated tubular member having aproximal portion, a distal tip end and a 3-D shaped portion; and atleast one ring electrode mounted on the 3-D shaped portion, wherein theproximal portion is in longitudinal alignment with the guide wire, andthe 3-D shaped portion extends around the guide wire.
 2. The ablationcatheter of claim 1, wherein the 3-D shaped portion coils around theguide wire.
 3. The ablation catheter of claim 1, wherein the 3-D portionincludes a helical configuration.
 4. The ablation catheter of claim 1,wherein the tubular member has one lumen adapted to receive the guidewire through the proximal portion.
 5. The ablation catheter of claim 4,wherein the at least one lumen has a first port in the proximal portionof the tubular member and a second port in the distal tip end, whereinone of the ports is adapted to allow the guide wire to exit the at leastone lumen to outside the tubular member and the other of the ports isadapted to allow the guide wire to enter the at least one lumen fromoutside the tubular member.
 6. The ablation catheter of claim 1, whereinthe proximal portion of the tubular member has at least a first outerband and the distal tip end has at least a second outer band, each ofthe bands tunnels adapted to receive the guide wire therethrough.
 7. Anablation catheter adapted for use with a guide wire, the cathetercomprising: an elongated tubular member having at least a first lumenextending therethrough, the elongated tubular member having a 3-D shapedportion; an elongated support member with shape memory extending throughat least a distal portion of the first lumen to support the 3-D shapedportion of the tubular member; at least one ring electrode mounted onthe 3-D shaped portion of tubular member, the at least one ringelectrode adapted for ablation; wherein a first portion of the tubularmember proximal of the 3-D shaped portion extends in longitudinalalignment with the tubular member, and the 3-D shaped portion of thetubular member coils around the guide wire.
 8. The catheter of claim 7,wherein the second lumen in the elongated tubular member proximal anddistal of the 3-D shaped portion are adapted to receive the guide wire.9. The catheter of claim 7, wherein the guide wire is outside of the 3-Dshaped portion.
 10. The catheter of claim 7, wherein the second lumenhas a first port proximal of the 3-D shaped portion and a second portdistal of the 3-D shaped portion, one of the ports adapted to allow theguide wire to exit from the second lumen to outside the tubular memberand another of the ports adapted to allow the guide wire to enter thesecond lumen from outside the tubular member.
 11. An ablation catheteradapted for use with a guide wire, the catheter comprising: an elongatedtubular member having at least first and second lumens extendingtherethrough, the elongated tubular member having a 3-D shaped portion;at least one ring electrode mounted on the 3-D shaped portion, the atleast one ring electrode adapted for ablation; and an elongated supportmember with shape memory extending through at least a distal portion ofthe first lumen, the elongated support member having a preformed 3-Dshape supporting the 3-D shaped portion, wherein the second lumen has aproximal port proximal of the 3-D shape and a distal port distal of the3-D shape, one port adapted to allow the guide wire to pass from insidethe second lumen to outside the tubular member, the other port adaptedto allow the guide wire to pass from outside the tubular member toinside the second lumen.
 12. The ablation catheter of claim 11, whereinthe catheter includes a distal tip end having an axial passage adaptedto allow the guide wire to pass through.
 13. The ablation catheter ofclaim 1, wherein the 3-D shape includes a helical configuration.
 14. Theablation catheter of claim 13, wherein the helical configuration isadapted to elongate axially and contract radially in a neutral state andto shorten axially and expand radially when subjected to a tensileforce.
 15. The ablation catheter of claim 13, wherein the helicalconfiguration is adapted to contact a plurality of radial locations onan inner surface of a vessel at different depth along the vessel. 16.The ablation catheter of claim 11, wherein the catheter includes atleast one lead wire for the at least one ring electrode, and the tubularmember includes a third lumen, the at least one lead wire extendingthrough the third lumen.
 17. An ablation catheter adapted for use with aguide wire, the catheter comprising: an elongated tubular member havingat least a first lumen extending therethrough, the tubular member havinga 3-D shaped portion; at least one ring electrode mounted on the 3-Dshaped portion, the at least one ring electrode adapted for ablation; anelongated support member with shape memory extending through at least adistal portion of the first lumen, the elongated support member having apreformed 3-D shape supporting the 3-D shaped portion; at least aproximal band proximal of the 3-D shaped portion and a distal banddistal of the 3-D shaped portion, the first and second bands adapted toallow the guide wire to pass therethrough.
 18. The ablation catheter ofclaim 17, wherein the catheter includes a distal tip band adapted toallow the guide wire to pass therethrough.
 19. The ablation catheter ofclaim 17, wherein the 3-D shape includes a helical configuration. 20.The ablation catheter of claim 19, wherein the helical configuration isadapted to elongate axially and contract radially in a neutral state andto shorten axially and expand radially when subjected to a tensileforce.